Abstract

Glyphosate is a widely used herbicide that can enter coastal waters through runoff, but its effects on the gut of benthic marine animals remain poorly understood. Sea cucumbers live on the seafloor and feed on sediment-associated material, making them a useful model for studying intestinal responses to waterborne pollutants. In this study, we exposed sea cucumbers to increasing concentrations of glyphosate in seawater for 24 h and then examined changes in intestinal metabolites and gene expression. Mortality occurred only at the highest exposure level, allowing us to compare surviving and dead individuals within the same treatment. We found clear dose-dependent molecular changes in the intestine, with the strongest disruption in dead individuals and an intermediate pattern in survivors. These changes were associated with altered energy and nutrient metabolism, lipid and amino acid pathways, and stress-related responses. Our results provide new mechanistic insight into how acute glyphosate exposure affects intestinal function in a marine deposit-feeding invertebrate and offer a foundation for future studies under more environmentally relevant conditions. Glyphosate is one of the most widely used herbicides worldwide and has been increasingly reported in aquatic environments, including riverine, estuarine, and coastal systems. However, information on its intestinal effects in benthic marine invertebrates remains limited. In this study, we investigated dose-dependent intestinal responses of the sea cucumber Apostichopus japonicus following acute waterborne glyphosate exposure using integrated transcriptomic and metabolomic analyses. Sea cucumbers were exposed for 24 h to four nominal glyphosate concentrations: 0, 9.23, 46.15, and 230.77 mg/L. Mortality occurred only in the highest-concentration group, allowing phenotypic stratification of this group into high-dose survivors (HL) and high-dose dead individuals (HD) for downstream multi-omics comparisons. Principal co